Related papers: High-resolution ro-vibrational and rotational spec…
The rovibrational spectrum of the molecular ion H$_2$CCCH$^+$ was investigated in a 4~K cryogenic ion trap instrument employing the leak-out spectroscopy method. Transitions within the fundamental $\nu_1$ (C-H stretch) and the combination…
Spectra of vibrational overtone and combination bands from vibrational ground state of HCNH+ were measured using an action spectroscopy technique with active background suppression in a cryogenic 22 pole radio frequency ion trap apparatus.…
Rotationally resolved spectra of the C$^2\Sigma^+$-X$^2\Pi$ electronic system of the CH radical were measured using cavity ring-down spectroscopy in supersonically expanding, planar hydrocarbon plasma. The experimental conditions allowed…
A cryogenic 22-pole ion trap apparatus is used in combination with a table-top pulsed IR source to probe weakly bound CH$^+$-He and CH$^+$-He$_4$ complexes by predissociation spectroscopy at 4 K. The infrared photodissociation spectra of…
The long-searched C-H stretches of the fundamental ions CH$^+$ and $^{13}$CH$^+$ have been observed for the first time in the laboratory. For this, the state-dependent attachment of He atoms to these ions at cryogenic temperatures has been…
Ever since they were first detected in the interstellar medium, the radio wavelength (3.3 GHz) hyperfine-structure splitting transitions in the rotational ground state of CH have been observed to show anomalous excitation. Astonishingly,…
Frequency-modulated diode laser transient absorption spectra of the ethynyl radical have been recorded at wavelengths close to 1.66 $\mu$m. The observed spectrum includes strong, regular, line patterns. The two main bands observed originate…
We discuss the detection of 14 rovibrational lines of CH$^+$, obtained with the iSHELL spectrograph on NASA's Infrared Telescope Facility (IRTF) on Maunakea. Our observations in the 3.49 - 4.13 $\mu$m spectral region, obtained with a 0.375"…
Rotational spectra in four new excited vibrational levels of the linear carbon chain radical C$_4$H radical were observed in the millimeter band between 69 and 364 GHz in a low pressure glow discharge, and two of these were observed in a…
The ethynyl radical cation, CCH$^+$ ($^3\Pi$), offers a unique system for fundamental spectroscopic studies of non-adiabatic effects due to its open-shell linear structure and the presence of a low-lying $^3\Sigma^-$ state, which induces…
HC$_3$N is an ubiquitous molecule in interstellar environments, from external galaxies, to Galactic interstellar clouds, star forming regions, and planetary atmospheres. Observations of its rotational and vibrational transitions provide…
Rotationally resolved spectra of the HNC$^+$ and HCN$^+$ molecular ions have been recorded in the spectral range between 6200 and 6800 \rcm\ using a cryogenic ion trap instrument. The rovibrational transitions were probed using two…
This work presents the rovibrational spectra of the two strongest first overtone bands of the asymmetric stretching mode $\nu_3$ ($2\nu_3^{2+}$ and $2\nu_3^{2-}$) of the hydronium ion, H$_3$O$^+$. The measurements were performed in a…
The CH$^+$ ion is a key species in the initial steps of interstellar carbon chemistry. Its formation in diverse environments where it is observed is not well understood, however, because the main production pathway is so endothermic (4280…
The methoxy radical, CH$_3$O, has long been studied experimentally and theoretically by spectroscopists because it displays a weak Jahn-Teller effect in its electronic ground state, combined with a strong spin-orbit interaction. In this…
Aims. Excitation of far-infrared and submillimetric molecular lines may originate from nonreactive collisions, chemical formation, or far infrared, near-infrared, and optical fluorescences. As a template, we investigate the impact of each…
We have started a measurement campaign of numerous methanol isotopologs in low-lying torsional states in order to provide extensive line lists for radio astronomical observations from an adequate spectroscopic model and to investigate how…
The pure rotational transitions of the protonated hydrogen cyanide ion, HCNH+, and its isotopic species, HCND+ and DCND+, were measured in the 107 - 482 GHz region with a source modulated microwave spectrometer. The ions were generated in…
The fundamental 28SiH+ ion has been characterized in a collaborative work, utilizing a hollow-cathode-discharge laser-spectrometer and a cryogenic ion trap spectrometer. Twenty-three vibration-rotation transitions around 4.75 um have been…
The chloroniumyl cation, HCl$^+$, has been recently identified in space from Herschel's spectra. A joint analysis of extensive vis-UV spectroscopy emission data together with a few high resolution and high accuracy mm-wave data provided the…